Electrical brake



Jan. 25, 1927,

H. V. MCCORMICK ELECTRICAL BRAKE Filed Feb. 25, 1924 2 Sheets-Sheet lInventor HAROLD V MCCQRM/cx.

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IIIIIIIIA u fill/lill l Jam 25, 1927. A H. V. MCCORMICK ELECTRICAL BRAKEFiled Feb. 25, 1924 2- sheets-sheet 2 Patented Jan. 25, 1927.

PATE-NT omen.

HAROLD V. MCCORMICKQ OF' CINCINNA'FI', OHIO; ASSIG-NOR'TO WARNERELEVATOR MANUFACTURING COMPANY, 0F CITGNNATI, OHO, A CORPORATION OFOHIO.

ELECTRICAL BRAKE.

An objet-tot` my invention istoprovidean electricalhrake `wherein fluidmeans may be employed for retarding thelotherwise rapid movementot` thearmature associated with such brake apparatus. f

Another object of my invention is to provide astructure Whereinthe-tinid retarding means becomes anintegral part ofthe armature foryeliminating vibra-tionfbetween them.

Another object of my invention is toV provide a structure thatwill electa slow movement of release and a rapid movement ot operation without theuse of checlcvalves Ol other meansot changing theeffect ot v`fluid flowfrom the fluid armature retarding means.

Another object isto provide means for clampingA the laminationsof alaminated steel. electromagnetic field f, and armature for securing thelaminations against'all lateral movement.

AnotherA object offiny invention is to provide aV simple and elificientdevice for the purposes as stated.

These and other object-s are lattained by meansdescrihedherein anddisclosed inthe accompanying drawings, in which:

Fig. 1 is aside elevation of the device embodying my invention.

Fig. 2' is a sectional-view on line 2,-2 of Fig. 1.

Fig. 3 is an elevation of an-electromagnet core forming a detail of myinvention.

Fig. 4 is an elevation showing at right angles thereto, the structuredisclosed in Fig, 3. h

Fig. 5 is a sectional view on line 5 5 ot Fig. 3,

G is an enlarged detail view of an armature forminga detail ofmyinvention.

Fig. 7 is a sectional view on line 7--7 ot Fig. 6.

Figs. 8 and 9 are diagrammatic views of wirings or coils forming detailsoft my invention.

The base 20' may be mounted on any suit-- able foundation 21 in anysuitable manner, for example as shown, and may be bolted thereto. Thecasing 22 comprises spaced sides 23 and rllhc base20 supports al casing22.V

Application ledebrnary'25, 1924. Seria1--Ngoz 695,123.

24. The sides are provided with openin s 25y therethrough and .a Shaft26 extends through said-openings, The shaft 26' carriesahdruln 27v1190,11 which brake shoes 28v from .displacement onlsaid casing. byprovid! a- .boss 36` uponv .the casing -and which boss may enter thecenter of the spring, Ahand lever 37 is provided wherebythe screwmaybeadjusted through the arm tormodifying thecompression of the spring.and consequently modifying the friction where with the. shoe 28 engagesthe drum. The upper end ofthe armf() is bifurcated, the branches 39 and40 thereotl supporting the pin 38.- The pin 38 is pivotally mounted uponthebranches 39and 40 and carries a block 41iiro1n which extends thescrew 42.

` Theblock is provided with bores 410 any of which will receivepin 38for adjustment of the lever 44.v The U-shaped lever 44 has its onebranch 45 adjustablymountedupon the screw 42 and may be secured vinadjusted positions by the nut 43. lt should be noted that this structure`gives a very elicient operating leverage'throug-h which the armaturesmayactvupon the brake shoes. The arm 46- of the lever 44- eXtendsthroughan opening 47 in the cover 48 of the casing 22 and carriesA adisc like flange Z 2 that serves as a closure tor opening 47. rlhecasing comprises internal ribs ortransversely eX- tending walls 49 and50. The ribs in part are spaced from the bottom 51 of thepcasingwherefore passages Vare provided between the chamber 53 at the center ofthe casing The second end of' the spring icc and the chambers 54 and 55formed in the casing 2Q exteriorly ot the walls or ribs 4!) and 50. Thewalls 49 and 50 are provided with apertures 56 through which plungers 57reciprocally extend, whereby a dash pot structure is provided betweenthe plunger and the wall as is disclosed in Fig. 2. The outer end ot'each plunger 57 is bifurcated and carries a pin 300 on which pin ispivotally mounted the branch 46 of the lever 44. The inner portion otthe plunger has mounted upon it a magnet field 58 comprising laminations59 secured between side plates 60 and 6l by any suitable means such asbolts and nuts (32 and all ot which constitutes an armature.

The walls 49 and 50 are provided with inwardly extending flanges 63 and64 for the reception of the magnet field, the recessed portions of thewall constitutes a retardation cylinder containing' the field orarmature. The field 58 is actuated by an electromagnet 66 disposedcentrally of thecasing 2Q. The electromagnet comprises laminations 67secured between end plates 68 and 69, which end plates are mounted uponthe casing. By reference to Fig. 3 it will be apparent that the corecomprising the laminations 67 and end plates is so constructed that 4notches are provided at the opposite edges et the cores, tor therecept-ion ot a pair of coils 70 and 71 at both sides ot the magnetcore. The coils may be electric-ally connected as shown in Figs. 8 and 9for effecting any desired phase operation. The casing contains aninsulating fluid such as oil and in which fluid the eleetromagnet andarmatures are immersed.

The sides 23 and 24 of the base 20 carry adjustment screws 73 forengagement upon the bralre shoes 28 and 29 for limiting the movement ofthe lower ends of' said brake shoes from the drum and for effectingadjustment ot' the bralre shoes to a concentric relationship to the drumand the shaft 26.

The operation of my device is as follows:

Normally the electromagnet is deener.

gized wherefore the brake shoes engage the drum and trictionally resistrotation of the drum. The springs 35 function as the means lor efiectingthis frictional resistance. When the drum is to be released theelectromagnet is energized whereupon the armatures or magnet fields aredrawn toward the electromagnet thereby moving the arms about theirpivotal mountings 3l and moving the brake shoes away from the drum. Thedash pot structure or retardation structure, in combination with theproportioning ot the levers and the co-acting 'forces pointed outherein, effects a slow release of the drum. lt will be observed thatwhen the drum is released the movement of the armature is resisted bothby the springs 35 and the flow oi the fiuid in the casing. When theelectromagnet is deencrgized the springs 35 return the parts to theirnormal positions. On deenergization ot the electromagnet the springsneed overcome only the resistance ot the dash pot structure whereby acomparatively rapid movement ot application of the brakes is effected.lt will be observed that by providing side plates between which thelaminations of the field or armature are bolted, all lateral movement ofthe laminations is precluded. It will be noted that no check valves arerequired for controlling the flow of duid in the casing yet a variationin the speeds of application and release of the brake is effected.

Attention is directed to the structures of the armature and magnet corestructures. it will be noted that the bolts that secure the laminationsdo not pass through perforations in the laminations but lie in slots atthe edges of the laminations. The slots are of a depth less than thediameters of the bolts wheretore the clamping means are isolated tromthe area ot luX as a result of which heating of the bolts is precluded.rlhis structure also has an advantage in that local actions or closedareas of excitation about the bolts are avoided, thereby eliminating thereduction in general etticiency and avoiding the undesirable localreactions incident to local actions. There is no flow of current throughthe bolts longitudinally and the presence of the bolts does not distortor modify the normal flux flow through the laminations.

What l claim is:

1. In a device of the class described the combination with a drum, ot' abrake shoe tor `trictional engagement with the drum, a lever pivotallymounted intermediate its ends and having the brake shoe mounted at itsone end, a U-shaped lever mounted at the second end of the firstmentioned lever, yielding means operative upon the rst mentioned levercausing the trictional engagement between the drum and the brake shoe, afluid containing casing, a wall eX- tending transversely ot' the casingand having a recess formed therein, a fiange extending from the wallforming a retardation cylinder, an armature having a rear platereciprocable through the retardation cylinder and recess and connectedwith the U- shaped lever, and an electromagnet infiuencing the movementof the armature and lever in one direction, and the retardation cylinderand recess modifying the action oit' the yielding means on the brakeshoe in the other direction.

2. In a device ot the class described the combination of a drum, a brakeshoe for trictional engagement upon the drum, means :tor actuating thebrake shoe and means for modifying the action of the brake shoeactuating means, the last mentioned means comprising a fluid containingcasing having a wall extending transversely of the easing, the Wallbeing provided with a recess, a flange extending from the Wall forproviding a retardation cylinder, an armature reeiproeable in theretardation cylinder and comprising a plate, the plate beingreciprocable in the recess, the recess and plate forming a dash potstructure whereby the brake shoe actuating means is Inodiied.

In testimony whereof, I have hereunto subscribed my naine this 8th dayof February, 1924.

HAROLD V. MCCORMICK.

